1. Field of the Invention
The present invention relates to an inkjet recording apparatus and a liquid application method, and more particularly to an ink droplet ejection control technology which achieves a function of ensuring the insolubility or fixing properties of a coloring material, by combining two types of liquid.
2. Description of the Related Art
In recent years, inkjet printers have come to be used widely as data output apparatuses for outputting images, documents, or the like. By driving recording elements, such as nozzles, provided in a recording head in accordance with data, an inkjet printer is able to form data onto a recording medium, such as recording paper by means of ink discharged from the nozzles.
An inkjet printer forms an image on recording paper by causing a recording head having a plurality of nozzles and a recording medium to move relative to each other, while causing ink droplets to be discharged from the nozzles.
There are various types of recording medium used in inkjet recording apparatuses, and by changing the ink type and altering the ink droplet ejection control in accordance with the type of recording medium used, a desirable image is formed on the recording medium.
For example, with a permeable type of medium in which deposited ink droplets permeate into the recording medium, a dye-based ink is used, in which the ink solute is maintained in an image receiving layer inside the recording medium, and the ink deposited onto the recording medium permeates rapidly into the recording medium, thereby reducing color aberrations and tone errors caused by disruption of dot shape, or superimposition of colors.
On the other hand, in the case of a non-permeable type of medium in which the deposited ink becomes fixed on the surface of the recording medium, a pigment-based ink is used, in which the ink solute solidifies on the surface of the medium. The ink is devised in such a manner that the water content is removed swiftly from the ink droplet deposited onto the recording medium, thereby causing the ink to become fixed.
In the inkjet printer apparatus and inkjet printer method disclosed in Japanese Patent Application Publication No. 8-281931, a print enhancing solution and ink are discharged onto the same position or mutually proximate positions, and while a portion of one of the previously discharged droplets of print enhancing solution or ink remains on the surface of the print medium, the other droplet is discharged.
Moreover, in the inkjet recording apparatus and inkjet recording method described in Japanese Patent Application Publication No. 2002-210947, an inkjet recording apparatus performs recording in a selected recording mode. In high-speed recording mode, the amount of ink ejected per pixel is less than that in low-speed recording mode, and when recording with black ink, a dissolution inhibitor solution is discharged.
Furthermore, in the inkjet method and inkjet recording apparatus described in Japanese Patent Application Publication No. 2002-321349, a recording head which discharges ink and a recording head which discharges treatment liquid for creating a prescribed action with respect to the coloring material of the ink are used, the amount of treatment liquid discharged being varied in accordance with the amount and type of the ink coloring material.
However, when various types of recording media are used, then the speed of permeation of the liquid droplets varies significantly, depending on the combination of recording medium and ink used. Therefore, it is necessary to control the amounts of treatment liquid and ink applied, in accordance with the combination of recording medium and ink. For example, the amount of liquid remaining on the recording medium after a prescribed time period will be different between the case of normal paper having rapid permeation properties and the case of coated printing paper having slow permeation properties. Therefore, unless suitable measures are taken with regard to the ejection droplet amount or processing of the remaining water content, in accordance with the type of recording medium, it will be difficult to form satisfactory images.
In the inkjet printer apparatus and inkjet printing method described in Japanese Patent Application Publication No. 8-281931, there is no disclosure regarding technology stating how to judge the time period during which liquid actually remains on the print medium, when the type of print medium is changed. Furthermore, in order to that both ink and a print enhancing solution can be discharged from the inkjet head, it is necessary for the print enhancing solution to have liquid properties (namely, viscosity, surface tension, etc.) which allow it to be discharged from the inkjet head.
Moreover, the inkjet recording apparatus and the inkjet recording method described in Japanese Patent Application Publication No. 2002-210947 disclose technology for controlling the amount of the ejected ink droplets in accordance with the selected recording mode, but there is no disclosure regarding technology for controlling the amount of the ejected droplets in accordance with the type of recording medium.
Furthermore, the inkjet method and the inkjet recording apparatus described in Japanese Patent Application Publication No. 2002-321349 disclose technology for controlling the amount of treatment liquid droplets in accordance with the amount and type of the ink coloring material, but there is no disclosure regarding technology for controlling the amount of the ejected droplets in accordance with the type of recording medium.